Overview
Seagulls belong to the Laridae family, the same family as terns. There are more than 50 species of seagulls which vary in color from black and white to gray and white. They are usually white on the underside and darker on the top of their bodies. This coloring acts as camouflage making it more difficult for fish to spot the birds against a pale sky. Seagulls can range in size from around 4 ounces to 4 pounds, depending on the species. These are heavy bodied species with webbed feet and slightly curved bills. They have been found to be highly intelligent, especially the larger species, showing signs of complex communicative behaviors and social interactions.
Seagulls are often associated with the ocean, but they can be found all over the world wherever there is a body of water including oceans, bays, rivers and lakes. Seagulls are most active during the day. At this time they forage for food, migrate and mate. Seagulls can be very aggressive and defensive, often displaying mobbing behavior against potential predators, including human predators. The life expectancy of a gull is dependent on species and surrounding environment, on average it ranges from 5 to 15 years there are records of some living as long as 25 years.
Diet
Seagulls are generalists, feeding and foraging on a variety of food. They practice kletoparasitism, which means they steal food from another animal that has already caught and killed the prey. The common diet of seagulls includes small crabs and fish. In many places, the diet of the seagull has been changed by the presence of humans. Seagulls are often seen panhandling from beachgoers, stealing from fishermen and foraging in dumpsters. In addition, seagulls demonstrate their intelligence by using rocks and other “tools” to crack open clams and other shellfish to reach the meat inside.
Mating and Reproduction
Seagulls nest in colonies at the same time every year. The entire colony helps to protect the nests from predators. Females lay between two and three eggs at a time. The eggs of most species hatch in 24-26 days. Hatchlings are usually darker in color allowing them to blend in with the surrounding nesting area. Chicks are guarded in the nesting sight until they lose their down, develop feathers and begin to fly. This can take from four to seven weeks.
Threats
The current greatest threat to seagulls is the loss of coastal habitat. Most seagulls nest in coastal areas and are losing more and more nesting grounds each year to human development. Other threats include pollution and incidental capture or entanglement in fishing gear. Some species of seagulls are handling these threats better than others. Currently, there are two species listed as endangered on the United Stated Endangered Species List; the Audouin’s gull and relict gull.